Shift from growth to nutrient-limited maintenance kinetics during biofilter acclimation

Abstract

During long‐term operation of a biofilter, the mandatory absence of net cell growth forces the cells into maintenance metabolism, which is of relatively low rate compared to substrate consumption during the active growth of the acclimation phase. A model based on this shift in metabolism can explain the postacclimation decrease in activity sometimes reported for biofilters. The cessation of growth can be caused by nutrient depletion in the bed. Postacclimation nutrient addition increases activity primarily by allowing a return to the high substrate consumption rate of active growth, and only secondarily helps raise bed activity because of the ultimately higher amount of biomass in the bed. Simulations incorporating the acclimation period and the role of maintenance metabolism predict about 4 logarithms of growth during acclimation of a hexane biofilter, which was confirmed experimentally. Changes in a biofilter's biomass during the acclimation phase can be estimated from substrate conversion data using two approximate methods. The first follows the cumulative amount of substrate converted and uses the estimated yield of cells from substrate during active growth to estimate the total biomass created. The second method follows a rate constant for conversion of substrate in the bed. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 330–339, 1997.

Degradation of Isobutanal at High Loading Rates in a Compost Biofilter

“…Table 1 30 all BFs normally operate under these stationary phase conditions, without net growth of the microorganisms, unless N is regularly supplied. This is also in accordance with the results of Demeestere et al, 18 who found that N limitation occurred in a methanol-degrading BF at nitrate concentrations Ͻ0.09 g NO 3…”

“…This threshold corresponds with the start of the stationary phase as mentioned by Cherry and Thompson. 30 Furthermore, it is believed that the IBAL removal in all of the BF sections was limited by a low compost N content, because from day 71, (NO 2 Ϫ ϩ NO 3 Ϫ )-N and NH 4 ϩ -N concentrations were mostly Ͻ0.05 g N/kg DW. Nitrogen limitation is additionally supported by the increase of the total IBAL removal efficiency after adding a nutrient solution to the compost material during period 3.…”

A Comprehensive Numerical Model Simulating Gas, Heat, and Moisture Transport in Sanitary Landfills and Methane Oxidation in Final Covers

“…The rate of oxidation of methane (R CH4 ), by assuming double Monod kinetics, is determined by [10]:…”

CO2 Response to Doses of Organic Solvents Biodegraded in a Batch Biofilter

“…Biofiltration of contaminants can be affected by the biofilter media, by the physiological conditions of the biomass, and by the physical conditions and processes inside a biofilter (Morgenroth et al, 1996;Cherry and Thompson, 1997;Auria et al, 2000;Aizpuru et al, 2003). There is very little known of the basic biological mechanisms essential to biofiltration (Furer and and even less known of the biodegradation kinetics of multiple contaminants in a biofilter.…”